With a plane arrival at 4 pm, by the time you clear customs, etc., you will be hitting the downtown traffic at just about the worst time. Traffic on lower Sukhemvit/Ploenchit can be pretty bad, and the situation you describe in your email is not unusual. The airport link would help, but if you are carrying a lot of luggage, it would be a pain as the transfer between the airport link and the BTS involves walking/steps, etc.

Take a look at this discussion thread. It should give you more info and help you decide which is the best way to go.

http://www.flyertalk.com/forum/thail...iscussion.html